Boot from USB using u-boot

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Revision as of 06:49, 13 October 2014 by Juzis28 (talk | contribs) (Prepare USB drive (and optionally TFTP))
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Note: This instruction apply and booting only to TV with firmwares listed below!

T-CHL7DEUC, T-CHEAUSC, T-CHL7DAUC (B650 and B750 series)

This is for advanced users and developers only.


  • Serial connection
  • Usb disk drive or pen drive (at least 256MB)
  • TFTP server outside TV on some host in case if you prefer load kernel from network (Do this only if you want faster kernel load or lack network).
  • Regular Linux based system to prepare usb disk/pen drive (disk drive is preffered for speed)
  • Builded rootfs image and kernel.

Follow steps:

Build OE kernel and rootfs

Or you can build your self from recent repository:

Builded rootfs image is located in build-samygo/tmp/deploy/images directory. File name looks like externalboot-base-rootfs-ssdtv-b650.tar.gz.

Prepare USB drive (and optionally TFTP)

  • Partition usb disk/pen drive.

Partition drive using fdisk or other tool.

First partition FAT type. It will be usefull or needed if you don't have network on tv. Second partition set as Linux type.

Format first partition with mtools or other tool as VFAT type filesystem. Format second partition with ext2fsprogs as ext3.

  • Unpack rootfs image to second partition on usb disk/pen drive with root rights
  • Follow two steps below only if you want install original samsung software (script can also download image from inside booted tv, but it's preffered download and copy into rootfs)
  • Download from here and place as is on /home/root
  • Get proper kernel image:

Find proper kernel image in build-samygo/tmp/deploy/images or download from .

It is: uImage- (it's for B750 too)

  • Put kernel image to proper place:

TFTP kernel load method

Copy kernel image into root directory of TFTP service directory like /tftpboot directory, or for NAS it is on /opt/tftpboot .

And rename kernel image to uImage .

USB kernel load method

Put kernel image on FAT partition (first).

And rename kernel image to uImage .

U-Boot shell

Booting TV

You can load and boot kernel from USB or TFTP:


Set network variables first:

setenv ipaddr;setenv gatewayip;setenv serverip

where first IP is TV, second gateway is not important in this case, third is address of TFTP server.

Boot linux kernel over TFTP and rootfs from USB ext3 partition:

setenv bootargs root=/dev/sda2 console=ttyS1;tftp;bootm


Boot linux kernel from USB FAT partition, rootfs from USB ext3 partition:

setenv bootargs root=/dev/sda2 rootdelay=1 console=ttyS1;usb start;fatload usb 0 61000000 uImage;bootm

where /dev/sda2 is linux rootfs.


If you have NFS server on your home network working, you can boot file system for TV (rootfs) and kernel from OE over NFS!

Prepare rootfs and kernel

  • Prepare USB drive, or you can simply extract rootfs.tar.gz from OE on your NAS directory:

(i use /mnt/disk1/TV_rootfs for filesystem)

cd /mnt/disk1/TV_rootfs
cp /<path to>/rootfs.tar.gz /mnt/disk1/TV_rootfs
tar xzf rootfs.tar.gz
  • Copy kernel file (uImage) to /mnt/disk1/TV_rootfs
 cp /<path to>/uImage /mnt/disk1/TV_rootfs
  • Edit exports to enable your rootfs and uImage on NFS

If you use filesystem on USB, attached to NAS:

root@LS-GL984:~# cat /etc/exports

If you use filesystem on NAS directory:

root@LS-GL984:~# cat /etc/exports

where is my TV IP. is submask, /mnt/usbdisk3 is my USB with TVs file system, /mnt/disk1/TV_rootfs - path to rootfs and kernel on NAS directory.

Boot kernel and rootfs over network

  • Enter to u-boot promt.
  • set network variables to load kernel
setenv ipaddr;setenv gatewayip;setenv serverip
  • set network variables to load rootfs
setenv bootargs root=/dev/nfs rw nfsroot= rootpath=/home/root ip= console=ttyS1

Now you have to boot kernel. Choose method you prefer (use NFS or TFTP)

  • load kernel over NFS and start booting TV
nfs 0x61000000;bootm
  • load kernel over TFTP and start booting TV

P.s. structure of commandline should for NFS should be:

setenv bootargs root=/dev/nfs rw nfsroot=${serverip} rootpath=${rootpath} ip=${ipaddr}:${serverip}:${gatewayip}:${netmask}:${hostname}:eth0:off  console=ttyS1

Where rootpath of OE kernel is /home/root

Starting main Samsung TV software

After boot system, login over serial console as root and execute followed commands:

  • Install Samsung original software:

Choose your firmware version:


--- Installer of Original Samsung Software ---
--- SamyGO ---

Select proper firmware for your TV:



Wait while TV installs firmware. It is quite long process, be patient.

  • Start Samsung original software:


NB! Kernel from OE does not support NAND writing and it does not help to restore bricked device.